/*
 * \addtogroup etimer
 * @{
 */

/**
 * \file
 * Event timer library implementation.
 * \author
 * Adam Dunkels <adam@sics.se>
 */

/*
 * Copyright (c) 2004, Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This file is part of the Contiki operating system.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 * $Id: etimer.c,v 1.3 2007/10/07 19:59:27 joxe Exp $
 */

/**
 * Adapted to MansOS by Girts Strazdins, 2012-07-16,
 * http://www.edi.lv/en/persons/girts-strazdins/
 */

//#include "contiki-conf.h"

// !!!
#include <stdmansos.h>

#include <kernel/protothreads/etimer.h>
#include <kernel/protothreads/process.h>
#include <timing.h>

static struct etimer *timerlist;
static clock_time_t next_expiration;
static bool et_polled;


PROCESS(etimer_process, "Event timer");
/*---------------------------------------------------------------------------*/
static void
update_time(void)
{
    clock_time_t tdist;
    clock_time_t now;
    struct etimer *t;

    if (timerlist == NULL) {
        next_expiration = 0;
    } else {

        now = clock_time();

        t = timerlist;
        /* Must calculate distance to next time into account due to wraps */
        tdist = t->timer.start + t->timer.interval - now;
        for(t = t->next; t != NULL; t = t->next) {
            if(t->timer.start + t->timer.interval - now < tdist) {
                tdist = t->timer.start + t->timer.interval - now;
            }
        }
        next_expiration = now + tdist;
    }
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(etimer_process, ev, data)
{
    struct etimer *t, *u;

    PROCESS_BEGIN();

    timerlist = NULL;
    et_polled = false;

    while(1) {
        PROCESS_YIELD();

        if(ev == PROCESS_EVENT_EXITED) {
            struct process *p = data;

            while(timerlist != NULL && timerlist->p == p) {
                timerlist = timerlist->next;
            }

            if(timerlist != NULL) {
                t = timerlist;
                while(t->next != NULL) {
                    if(t->next->p == p) {
                        t->next = t->next->next;
                    } else
                        t = t->next;
                }
            }
            continue;
        } else if(ev != PROCESS_EVENT_POLL) {
            continue;
        }

        again:

        u = NULL;

        for(t = timerlist; t != NULL; t = t->next) {
            if(timer_expired(&t->timer)) {
                if(process_post(t->p, PROCESS_EVENT_TIMER, t) == PROCESS_ERR_OK) {

                    /* Reset the process ID of the event timer, to signal that the
                       etimer has expired. This is later checked in the
                       etimer_expired() function. */
                    t->p = PROCESS_NONE;
                    if(u != NULL) {
                        u->next = t->next;
                    } else {
                        timerlist = t->next;
                    }
                    t->next = NULL;
                    update_time();
                    goto again;
                } else {
                    etimer_request_poll();
                }
            }
            u = t;
        }

        et_polled = false;
    }

    PROCESS_END();
}
/*---------------------------------------------------------------------------*/
void
etimer_request_poll(void)
{
    process_poll(&etimer_process);
}
/*---------------------------------------------------------------------------*/
static void
add_timer(struct etimer *timer)
{
    struct etimer *t;

    etimer_request_poll();

    if(timer->p != PROCESS_NONE) {
        /* Timer not on list. */

        for(t = timerlist; t != NULL; t = t->next) {
            if(t == timer) {
                /* Timer already on list, bail out. */
                update_time();
                return;
            }
        }
    }

    timer->p = PROCESS_CURRENT();
    timer->next = timerlist;
    timerlist = timer;

    update_time();
}
/*---------------------------------------------------------------------------*/
void
etimer_set(struct etimer *et, clock_time_t interval)
{
    timer_set(&et->timer, interval);
    add_timer(et);
}
/*---------------------------------------------------------------------------*/
void
etimer_reset(struct etimer *et)
{
    timer_reset(&et->timer);
    add_timer(et);
}
/*---------------------------------------------------------------------------*/
void
etimer_restart(struct etimer *et)
{
    timer_restart(&et->timer);
    add_timer(et);
}
/*---------------------------------------------------------------------------*/
void
etimer_adjust(struct etimer *et, int timediff)
{
    et->timer.start += timediff;
    update_time();
}
/*---------------------------------------------------------------------------*/
int
etimer_expired(struct etimer *et)
{
    return et->p == PROCESS_NONE;
}
/*---------------------------------------------------------------------------*/
clock_time_t
etimer_expiration_time(struct etimer *et)
{
    return et->timer.start + et->timer.interval;
}
/*---------------------------------------------------------------------------*/
clock_time_t
etimer_start_time(struct etimer *et)
{
    return et->timer.start;
}
/*---------------------------------------------------------------------------*/
int
etimer_pending(void)
{
    return timerlist != NULL;
}
/*---------------------------------------------------------------------------*/
clock_time_t
etimer_next_expiration_time(void)
{
    return etimer_pending() ? next_expiration : 0;
}
/*---------------------------------------------------------------------------*/
void
etimer_stop(struct etimer *et)
{
    struct etimer *t;

    /* First check if et is the first event timer on the list. */
    if(et == timerlist) {
        timerlist = timerlist->next;
        update_time();
    } else {
        /* Else walk through the list and try to find the item before the
       et timer. */
        for(t = timerlist; t != NULL && t->next != et; t = t->next);

        if(t != NULL) {
            /* We've found the item before the event timer that we are about
               to remove. We point the items next pointer to the event after
               the removed item. */
            t->next = et->next;

            update_time();
        }
    }

    /* Remove the next pointer from the item to be removed. */
    et->next = NULL;
    /* Set the timer as expired */
    et->p = PROCESS_NONE;
}
/*---------------------------------------------------------------------------*/
bool etimer_polled() {
    return et_polled;
}
/*---------------------------------------------------------------------------*/


/** @} */

